1. Field of the Invention
The present invention relates generally to electronic blood pressure monitors and particularly to electronic blood pressure monitors having a blood pressure measurement function as well as a function associated with erasing a measured value and/or changing a set value.
2. Description of the Background Art
Typically household electronic blood pressure monitors have a function storing measured blood pressure data and displaying a previously measured blood pressure value. If one is given such a blood pressure monitor he/she may desire to erase previous measurement data stored therein. Accordingly, conventionally there exists an electronic blood pressure monitor having a function erasing previous measurement data.
For example Japanese Patent Laying-Open No. 2005-224440 discloses a blood pressure monitor that can erase only a resultant measurement stored in memory that the user desires to erase. The user can erase only the others' measurement data.
Furthermore, there exists a blood pressure monitor having a function storing blood pressure data in association with date, time and other similar conditions for measurement and displaying a previous blood pressure value in association with such condition in the measurement. Such blood pressure monitor further has a function for example setting and changing before blood pressure measurement a value serving as a reference for a condition for measurement.
For example Japanese Patent Laying-Open Nos. 2002-272686 and 2002-272687 describe that a blood pressure monitor includes a switch operated to set and correct a time and a fast forward and reverse switch fast forwarding or reversing a time in setting and correcting it. The publications disclose that the switches can be operated to change date and time. If the blood pressure monitor has an incorrect date and time, the user can correct it. This can prevent a blood pressure value from being stored with an incorrect date and time (or a condition for measurement).
Allowing a user to freely erase measurement data and change a set value, as described above, however, can be inconvenient to a doctor or a similar supervisor of a subject. For example if the supervisor instructs the subject to measure blood pressure everyday, then, normally, the supervisor can obtain a resultant measurement in a subsequent day to for example see how the subject's blood pressure varies. However, if measurement data can be erased, as desired, and the subject is unsatisfied with the resultant measurement, the subject may erase the data of the resultant measurement, resulting in falsified measurement data.
Furthermore if the supervisor instructs the subject to measure blood pressure during a designated period of time the subject can change the set time to falsify the time of measurement.